David has some marbles.He gave 2/5 of his marble to his neighbour and 1/6 of the remainder to his friend Ali.He had 25 marbles l
1 answer:
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Using the z-distribution, we have that:
a)
The hypothesis test is:
The p-value is of 0.0668.
The critical value is
b) Since the <u>test statistic is less than the critical value</u> for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.
Item a:
At the null hypothesis, it is <u>tested if the mean is of 7.4 minutes</u>, that is:
At the alternative hypothesis, it is <u>tested if the mean is lower than 7.4 minutes</u>, that is:
We have the <u>standard deviation for the population</u>, hence, the z-distribution is used.
The test statistic is given by:
The parameters are:
is the sample mean.
is the value tested at the null hypothesis.
is the standard deviation of the sample.
- n is the sample size.
For this problem, the values of the <em>parameters </em>are: .
Hence, the value of the <em>test statistic</em> is:
Using a z-distribution calculator, the p-value is of 0.0668.
Also using a calculator, considering a <u>left-tailed test</u>, as we are testing if the mean is less than a value, the critical value with a <u>significance level of 0.1</u> is of .
Item b:
Since the <u>test statistic is less than the critical value</u> for the left-tailed test, there is enough evidence to conclude that the null hypothesis will be rejected.
You can learn more about the use of the z-distribution to test an hypothesis at brainly.com/question/16313918
Answer:
Option 2 - Approximately 24–36 pounds
Step-by-step explanation:
Given : A standard American Eskimo dog has a mean weight of 30 pounds with a standard deviation of 2 pounds. Assuming the weights of standard Eskimo dogs are normally distributed.
To find : What range of weights would 99.7% of the dogs have?
Solution :
The range of 99.7% will lie between the mean ± 3 standard deviations.
We have given,
Mean weight of Eskimo dogs is
Standard deviation of Eskimo dogs is
The range of weights would 99.7% of the dogs have,
Therefore, The range is approximately, 24 - 36 pounds.
So, Option 2 is correct.